Strainer for liquid pipe lines

ABSTRACT

The invention relates to a strainer for fluid pipe lines containing a filter element coaxial with the pipe line and a fluid deflector. The latter causes the incoming fluid first to flow around the filter element in a direction substantially parallel to its axis and thereafter to flow perpendicular through it and out of its downstream end. The filter element is constituted by a plurality of juxtaposed grooved washers.

UnitedStates Patent [1 1 Drori 1 STRAINER FOR LIQUID PIPE LINES [76]Inventor: Mordeki Drori, 89 Zahal St., Kiron,

Israel [22] Filed: Nov. 10, 1971 211 Appl. No.: 197,305

[30] Foreign Application Priority Data Nov. 15, 1970 Israel 35651 [52]U.S. Cl 210/310, 210/313, 210/448,

[51] Int. Cl B0ld 25/00 [58] Field of Search... 210/310, 313, 446, 448,488

[ 56] References Cited UNITED STATES PATENTS 3,397,794 8/1968 Toth eta1. 210/446 X 3,355,021 11/1967 Jones 210/446 X 3,048,276 8/1962 Darnell210/488 X Feb. 5, 1974 1,496,771 6/1924 Cash 210/310 X 327,646 10/1885Bingham, Jr 210/446 X 2,305,351 12/1942 Hellan 210/313 X PrimaryExaminer-Samih N. Zahama Assistant Examiner-Richard W. Burks Attorney,Agent, or Firm-Benjamin J. Barish [57] ABSTRACT The invention relates toa strainer for fluid pipe lines containing a filter element coaxial withthe pipe line and a fluid deflector. The latter causes the incomingfluid first to flow around the filter element in a directionsubstantially parallel to its axis and thereafter to flow perpendicularthrough it and out of its downstream end.

The filter element is constituted by a plurality of juxtaposed groovedwashers.

8 Claims, 2 Drawing Figures STRAINER FOR LIQUID PIPE LINES The presentinvention concerns pipe line strainers or filters which are used in pipelines carrying fluids such as water, petroleum, foodstuffs, chemicals,gases or the like, with a view to remove dirt or otherentrainmenttherefrom.

The known strainers generally comprise a cylindrical filter element ofplastic or metal mesh which is inserted into the pipe line at an anglein such a manner that the oncoming fluid is forced against the wall ofthe screen mesh and then flows through it into the continuation of thepipe line. A trap or sump is provided at the bottom of the screen fromwhich the accumulated dirt can be removed from time to time.

These strainers have a number of serious drawbacks. Their filterelements wear out quickly since they are disposed in the direct path ofthe inflowing fluid. This fact also causes clogging of the filterelement, reducing the efficiency of the strainer very quickly even atthe beginning of operation of the strainer and forcing the fluid to finda path through other parts of the filter. Cleaning of the filter canonly be effected when the element is removed from the strainer housingand this removal is a complicated procedure, entrailing in many casesthe entire dismantling of the strainer from the pipe line.

It is the object of the invention to provide a strainer whose efficiencyis substantially the same throughout its operation.

It is a further object of the present invention to provide a strainerfor fluid pipe lines in which the flow of the fluid is deflected, beforeit flows through the filter element in such a manner that it does nothit the filter element at an angle but flows parallel to its axis allaround its cylindrical filtering surface and thereby can flush saidsurface continuously so that little clogging can occur.

It is a further object of the present invention to provide a strainerwhich can be cleaned quickly and easily without removing the entirestrainer from the pipe line.

It is still a further object of the present invention to provide astrainer which takes up little space beyong the confines of the pipeitself.

The invention consists in a strainer for fluid lines in which the filterelement is coaxial with the pipe line, and a coaxial fluid deflector isprovided upstream of the upstream end of the filter element in such amanner that the incoming fluid is deflected and made to flow around thefilter element substantially parallel to its axis before it flowsperpendicularly through it and out of its downstream end.

More particularly, the novel strainer or filter comprises an inner rigidsupporting body and pipe connecting means fixed to both its ends forconnecting same to the two fluid pipes. The filter is supported aroundthe rigid supporting body. An outer tubular housing is removablysupported on the inner body and radially spaced therefrom and the filterto define an outer axial passageway between the external face of thefilter and the internal face of the housing. The inner rigid supportingbody is formed with an inner axial passageway, and is further formedwith a radial passageway in the portion thereof occupied by the filter,the radial passageway, effecting communication between the outer andinner axial passageways via the filter. A deflector closes the inneraxial passageway of the inner supporting body at one end and therebyforces the fluid to flow from the upstream pipe serially through oneaxial passageway, the filter, the radial passageway, and the other axialpassageway before reaching the downstream pipe.

An important feature of the invention is that the inner rigid supportingbody, and the pipe connecting means carried at the opposite endsthereof, effect a rigid mechanical connection between the two pipesindependently of the housing. Thus, the housing may be easily removed toenable cleaning the filter without disconnecting the two pipes. Inaddition, the housing may be made of inexpensive plastic material sinceit is not required to withstand the axial load to which the strainer issubjected by the two fluid pipes.

The filter element may be constituted by a plurality of juxtaposedgrooved washers, as known per se, or by a screen mesh.

Owing to this construction, the fluid as it flows into the strainer doesnot impinge directly on the filter element but first flows around it, sothat the impurities will not become entrained in the filter-element andclog it but will continuously be flushed away by further fluid. Also,the housing may be easily removed to enable cleaning the filter withoutdisconnecting the two pipes, as described above.

The invention is illustrated, by way of example only, in theaccompanying drawings, in which:

FIG. 1 is a longitudinal section of a strainer according to theinvention attached to a pipeline.

H6. 2 is a cross-section thereof taken on line -11 of FIG. 1.

The strainer here illustrated comprises a socket 1 having an internalscrew-thread 2 for attaching the strainer by screwing onto ahorizontally extending inlet pipe 3, ribs 4 being provided on its outersurface to facilitate the turning of the socket. The walls of the socketflare outwardly at 5 and are undercut at their ends to provide ashoulder 6 and perpendicular thereto a threaded surface 7 to which theannular upstream end 8 of the filter-supporting body 9 is screwed. Thisbody is constituted by elongated, axially extending, radially spacedribs 10 which are integral with the internal surface of an annulus 1 lat their upstream end and integral with a sleeve 12 at their trailingend, the external diameter of sleeve 12 being substantially equal withthe internal diameter of annulus l 1, so that the latter projectsradially beyond the ribs 10. Annulus 11 is integral with upstream end 8by means of a number of radially spaced ribs 13 and has an internalscrew-thread near its upstream end for the attachment by screwing of aconical deflector 14 which is coaxial with and faces the inlet pipe 3.The downstream or trailing end of sleeve 12 is internally threaded toreceive the threaded end of the outlet pipe 15.

A cylindrical filter element 16 composed of a plurality of groovedwashers tightly juxtaposed, as known per se, is supported on ribs 10 andabuts annulus 11. A cylindrical mesh-screen likewise as known per se,may replace filter element 16, if desired. The filter element is held inplace by a retaining ring 17 attached by screwing to the outside ofsleeve 12.

A substantially cylindrical housing 18 is attached by screwing with itsupstream end to an undercut externally threaded part 8' of upstream end8 of filtersupporting body 9. The downstream end of housing 18 is ofreduced diameter and abuts with its internal peripher-y the externalperiphery of ring 17, an O-ring l9 housed within an annular groove inring 17 providing a seal.

Housing 18 is integral with a co-axial substantially cylindrical sump 20which is in communication with the interior of the housing by means ofan opening 21 extending axially over the entire length of the filter 16.Sump 20 is closed at the upstream end of the strainer by an integralwall 20 and at the downstream end of the strainer is provided with acock 22 having a large downwardly extending outlet opening 23. Furtherrings are provided in the assembly of the strainer wherever a tight sealis required, as known per se.

Thus, it will be seen that body 9, including its radial ribs 13,annulus, 1 l, axial ribs 10, sleeve 12 and retaining ring 17, togetherform an inner rigid supporting body effecting a rigid mechanicalconnection between the upstream pipe 3 and the downstream pipe 15. Thisrigid mechanical connection is independent of housing 18, and thereforethe housing may be removed to enable cleaning the filter elements 16without disconnecting the two pipes from the rigid supporting body. Thisgreatly facilitates cleaning of the filter. in addition, since housing18 does not have to withstand the axial load between the two pipes (e.g.resulting from the expansion and contraction of the pipes arising fromtemperature changes), the housing may be made of inexpensive (e.g.plastic) material.

It will further be seen that the cone-shaped deflector l4 directs thefluid to flow from the up-stream pipe 3 through the space between ribs13 to the outer axial passageway 30 between the external face of filterl6 and the internal face of housing 18. The fluid is then directed toflow serially through the filter 16, the radial passageways formed bythe spaces between axial ribs 10 of the inner rigid supporting body, andthen through axial passageway 32 formed through the inner rigidsupporting body before finally reaching the downstream pipe 15.

The fluid flowing from pipe 3 is deflected by deflector 14 and is madeto flow by way of ribs 13 all around filter element 16 and through it tooutlet pipe 15. Any impurities which are momentarily deposited on theouter surface of the filter element are continuously flushed awaytherefrom by the flowing fluid in a selfflushing action and drop bygravity through opening 21 into sump 20. After a quantity of impuritieshas accumulated in the sump, cock 22 is opened to permit the fluid toflush them out through outlet opening 23.

If impurities become entrained on the surface of the filter element 16,the latter can be easily cleaned by removing housing 18 from body 9 byunscrewing and sliding the housing onto pipe 15, whereby the filterelement is exposed and can be brushed clean, without removing the entirestrainer from its connection with the pipes 3 and 15. A removal of ring17 by unscrewing it from sleeve 12 will permit a flushing of the groovedwashers of filter element 16 in case the grooves of said washers becomeclogged.

if desired, the cock 22 can be automatically operated by any known meansafter a predetermined time period or a predetermined density of theimpurities which have collected in the sump 20.

I claim:

1. A strainer connectable between two fluid pipes, comprising: an innerrigid supporting body; pipe connecting means fixed to said inner body atboth ends for connecting same to the two fluid pipes; a filter supportedaround said inner body; an outer tubular housing removably supportedaround said inner body and radially spaced therefrom and the filtersupported thereby, to define an outer axial passageway between theexternal face of the filter and the internal face of the housing; saidinner supporting body being formed with an inner axial passageway, andbeing further formed with a radial passageway in the portion thereofoccupied by said filter, the radial passageway effecting communicationbetween said outer and inner axial passageways via said filter; and adeflector closing the inner axial passageway of the inner supportingbody at one end and forcing the fluid to flow from the upstream pipeserially through one axial passageway, the filter, the radialpassageway, and the other axial passageway before reaching thedownstream pipe; said inner rigid supporting body and said pipeconnecting means carried at the opposite ends thereof effecting a rigidmechanical connection between said two pipes independently of saidhousing whereby the housing may be removed to enable cleaning the filterwithout disconnecting the two pipes.

2. A strainer as defined in claim 1, wherein the upstream end of theinner rigid supporting body includes an annular ring of larger diameterthan the remainder of the supporting body and fixed thereto by aplurality of angularly-spaced, radially-extending ribs, the spacebetween said ribs providing communication from the upstream pipe to saidouter axial passageway.

3. A strainer as defined in claim 2, wherein said deflector comprises acone-shaped member threadedly received in the up-stream end of the innerrigid supporting body closing said end thereof and thereby directing thefluid to flow from the upstream pipe through the space between the ribsto the outer axial passageway.

4. A strainer as defined in claim 1, wherein one end of said outertubular housing is threadely received on one end of the inner rigidsupporting body, the opposite end of the housing being unattached to theopposite end of the body but sealed with respect thereto by a sealingring.

5. A strainer as defined in claim 1, wherein said inner rigid supportingbody includes annular end portions at each end integrally joined with anintermediate portion, the latter being formed with a plurality of saidradial passageways.

6. A strainer as defined in claim 5, wherein said intermediate portionof the inner rigid supporting body includes a plurality of axiallyextending ribs angularly spaced from each other, the spaces between saidlatter ribs defining said radial passageways.

7. A strainer as defined in claim 1, wherein said filter comprises aplurality of grooved annular washers supported by said inner rigidsupporting body.

8. A strainer as defined in claim 1, wherein said outer tubular housingincludes a sump at the bottom thereof and extending parallel to the axisof the housing, said outer axial passageway communicating with said sumpover substantially the complete length of said filter, the downstreamend of the sump being closed by an axially movable cock.

1. A strainer connectable between two fluid pipes, comprising: an innerrigid supporting body; pipe connecting means fixed to said inner body atboth ends for connecting same to the two fluid pipes; a filter supportedaround said inner body; an outer tubular housing removably supportedaround said inner body and radially spaced therefrom and the filtersupported thereby, to define an outer axial passageway between theexternal face of the filter and the internal face of the housing; saidinner supporting body being formed with an inner axial passageway, andbeing further formed with a radial passageway in the portion thereofoccupied by said filter, the radial passageway effecting communicationbetween said outer and inner axial passageways via said filter; and adeflector closing the inner axial passageway of the inner supportingbody at one end and forcing the fluid to flow from the upstream pipeserially through one axial passageway, the fiLter, the radialpassageway, and the other axial passageway before reaching thedownstream pipe; said inner rigid supporting body and said pipeconnecting means carried at the opposite ends thereof effecting a rigidmechanical connection between said two pipes independently of saidhousing whereby the housing may be removed to enable cleaning the filterwithout disconnecting the two pipes.
 2. A strainer as defined in claim1, wherein the upstream end of the inner rigid supporting body includesan annular ring of larger diameter than the remainder of the supportingbody and fixed thereto by a plurality of angularly-spaced,radially-extending ribs, the space between said ribs providingcommunication from the upstream pipe to said outer axial passageway. 3.A strainer as defined in claim 2, wherein said deflector comprises acone-shaped member threadedly received in the up-stream end of the innerrigid supporting body closing said end thereof and thereby directing thefluid to flow from the upstream pipe through the space between the ribsto the outer axial passageway.
 4. A strainer as defined in claim 1,wherein one end of said outer tubular housing is threadely received onone end of the inner rigid supporting body, the opposite end of thehousing being unattached to the opposite end of the body but sealed withrespect thereto by a sealing ring.
 5. A strainer as defined in claim 1,wherein said inner rigid supporting body includes annular end portionsat each end integrally joined with an intermediate portion, the latterbeing formed with a plurality of said radial passageways.
 6. A straineras defined in claim 5, wherein said intermediate portion of the innerrigid supporting body includes a plurality of axially extending ribsangularly spaced from each other, the spaces between said latter ribsdefining said radial passageways.
 7. A strainer as defined in claim 1,wherein said filter comprises a plurality of grooved annular washerssupported by said inner rigid supporting body.
 8. A strainer as definedin claim 1, wherein said outer tubular housing includes a sump at thebottom thereof and extending parallel to the axis of the housing, saidouter axial passageway communicating with said sump over substantiallythe complete length of said filter, the downstream end of the sump beingclosed by an axially movable cock.